Wide field-of-view reflector and method of designing and making same

• US 8,471,892 B2
• Filed: 11/21/2007
• Issued: 06/25/2013
• Est. Priority Date: 11/23/2006
• Status: Expired due to Fees

• Current Assignee: Geng Z. Jason
• Original Assignee: Geng Z. Jason
• Inventors: Geng, Z. Jason
• Primary Examiner(s): NGUYEN, MINH CHAU
• Application Number:
  US11/984,702
• Publication Number:
  US 20080122922A1
• Time in Patent Office: 2,043 Days
• Field of Search: 348/146, 348/36, 348/39
• US Class Current: 348/36
• CPC Class Codes: G08B 13/19628 of wide angled cameras and camera groups, e.g. omni-directional cameras, fish eye, single units having multiple cameras achieving a wide angle view
• CPC Class Codes: G08B 13/19643 wherein the cameras play different roles, e.g. different resolution, different camera type, master-slave camera
• CPC Class Codes: G08B 13/19697 Arrangements wherein non-video detectors generate an alarm themselves
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A system and method for designing and using freeform reflectors to collect images of a wide angle field-of-view scene is provided. A freeform reflector may enable a wide angle field-of-view to be collected in an unwarpped and unwrapped manner such that computer processing may be eliminated. Furthermore, the use of a freeform reflector allows for larger areas of an image sensor chip to be used, thereby providing higher resolution images. Because freeform reflectors may be configured to map a scene onto the image sensor chip in a scalar and mathematically correct manner, output images may be directly displayed from the image sensor chip. Wide angle field-of-view imaging systems, such as surveillance, alarm, and projector system, may utilize freeform reflectors as provided herein.

Claims

1. A wide angle reflector device, comprising:

a freeform surface being reflective and having a shape defined by a mapping to reflect and map a light beam onto a sensor defined by pixels arranged in a predetermined shape, the freeform surface having a physical geometric configuration that maps the scene onto the sensor substantially free of distortion.

2. The reflector device according to claim 1, wherein the reflective surface is an optical reflective surface.

3. The reflector device according to claim 2, wherein the light beam defines an optical image having a field-of-view between approximately 30 degrees up to approximately 120 degrees.

4. The reflector device according to claim 1, wherein the mapping causes the light beam to be redistributed when imaged on the sensor.

5. The reflector device according to claim 4, wherein the redistribution of the light beam implements a mathematical function such that the light beam mapped onto the sensor is a corrected signal that does not need to be corrected digitally or otherwise.

6. The reflector device according to claim 1, wherein the sensor is a CCD or CMOS image sensor chip.

7. The reflector device according to claim 6, wherein reflector is configured to reflect a wide angle field-of-view image that covers substantially the entire image sensor chip.

8. The reflector device according to claim 1, wherein the reflector has a surface that is curvilinear.

9. The reflector device according to claim 8, wherein the surface includes linear and non-linear regions.

10. The reflector device according to claim 1, wherein the light beam defines and optical image having a field-of-view ranging up to 360 degrees.

11. The reflector device according to claim 1, wherein the mapping defines a predetermined distribution of the light beam onto the sensor.

12. The reflector device according to claim 1, wherein the predetermined distribution of the light beam is scalar and mathematically correct.

13. The reflector device according to claim 1, wherein the predetermined shape of pixel arrangement is a geometric shape.

14. The reflector device according to claim 1, wherein the reflector has a surface profile defined by vector manipulation of an incident ray and a reflected ray to compute a normal vector.

15. The reflector device according to claim 1, wherein the reflector has a surface freeform surface that is defined by a composite of normal vectors across reflection points.

16. The reflector device according to claim 1, wherein the reflector has a surface defined by mapping source points along a panoramic cylinder onto the sensor.

17. The reflector device according to claim 1, wherein the reflector has a surface that is a function of how a designer desires to map a scene on the sensor.

18. The reflector device according to claim 1, wherein the sensor converts mapped images received into electronic signals that are displayed by an electronic display.

19. The reflector device according to claim 1, wherein the reflector surface shape allows an image sensing system in which the reflector is included to operate without out any moving parts.

20. The reflector device according to claim 1, wherein the sensor has a predetermined shape.